Generally, a storage device, such as a vegetable box of a refrigerator, is equipped with a roller assembly for smooth movement during storage.
A conventional roller assembly includes a shaft configured to be coupled to the main body of a refrigerator and a roller configured to be rotatably installed at the outer end of the shaft. In connection with this, such conventional roller assemblies have been disclosed in Korean Utility Model Registration No. 20-0452543, Korean Patent No. 10-1437957, Korean Patent No. 10-0908659, and Korean Patent No. 10-0822749.
However, in the above-described conventional roller assemblies, the load applied to the shaft from the roller increases as the amount of stock stored in a storage device to which the roller is applied increases, and the load is concentrated only in a specific region between the roller and the shaft. Accordingly, problems arise in that a rolling operation is not smoothly performed and noise is generated.
Of course, conventionally, a rolling bearing having an inner ring and an outer ring is disposed between the contact surfaces of a roller and a shaft in order to prevent the above-described problems. In connection with this, related technologies have been disclosed in Korean Utility Model Registration Application Publication No. 20-2010-0000325, Korean Patent Application Publication No. 10-2014-0088395, Korean Patent No. 10-0159907, and Korean Patent No. 10-0402487.
However, the roller assemblies in which the rolling bearing is additionally disposed as described above have a problem in that, in light of the fact that the rolling bearing has been assembled using a method of press-fitting it between the roller and the shaft, it is extremely difficult to perform the operation of press-fitting the rolling bearing unless the outer diameter of the outer ring forming a part of the rolling bearing is formed into a precise size or unless the inner circumferential surface of the roller or the outer circumferential surface of the shaft is formed into a precise size.
Furthermore, when the above-described press-fitting of the rolling bearing is not accurately performed, a problem arises in that the smooth rolling of the roller is not performed or the like.
Moreover, the above-described conventional roller assemblies including a rolling bearing have a problem in that the rolling bearing is moved from an accurate location and then separated when an external impact, an excessive load, or the like is continuously applied or when the roller is operated in an inaccurate position, such as the position in which the roller rolls in the state of being inclined toward one side.